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error HP
Error Code Er/07
Cartridge missing or incorrectly installed — printer not detecting ink cartridges properly.
? What Causes This
Inadequate installation, improper contact between cartridge and print head.
✓ How to Fix It
Ensure correct installation of the ink cartridge following steps in Setup Guide.
Source: page 2 of the official manual
From the manual
This error code appears in:
HP Laserjet Mfp M139e M142e Printer